[PATCH] Add ixp4xx HW RNG driver

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/hw_random/Kconfig

@@ -61,3 +61,16 @@ config HW_RANDOM_VIA
 	  module will be called via-rng.
 
 	  If unsure, say Y.
+
+config HW_RANDOM_IXP4XX
+	tristate "Intel IXP4xx NPU HW Random Number Generator support"
+	depends on HW_RANDOM && ARCH_IXP4XX
+	default y
+	---help---
+	  This driver provides kernel-side support for the Random
+	  Number Generator hardware found on the Intel IXP4xx NPU.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ixp4xx-rng.
+
+	  If unsure, say Y.

drivers/char/hw_random/Makefile

@@ -7,3 +7,4 @@ obj-$(CONFIG_HW_RANDOM_INTEL) += intel-rng.o
 obj-$(CONFIG_HW_RANDOM_AMD) += amd-rng.o
 obj-$(CONFIG_HW_RANDOM_GEODE) += geode-rng.o
 obj-$(CONFIG_HW_RANDOM_VIA) += via-rng.o
+obj-$(CONFIG_HW_RANDOM_IXP4XX) += ixp4xx-rng.o

drivers/char/hw_random/ixp4xx-rng.c

+/*
+ * drivers/char/rng/ixp4xx-rng.c
+ *
+ * RNG driver for Intel IXP4xx family of NPUs
+ *
+ * Author: Deepak Saxena <dsaxena@plexity.net>
+ *
+ * Copyright 2005 (c) MontaVista Software, Inc.
+ *
+ * Fixes by Michael Buesch
+ *
+ * This file is licensed under  the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/bitops.h>
+#include <linux/hw_random.h>
+
+#include <asm/io.h>
+#include <asm/hardware.h>
+
+
+static int ixp4xx_rng_data_read(struct hwrng *rng, u32 *buffer)
+{
+	void __iomem * rng_base = (void __iomem *)rng->priv;
+
+	*buffer = __raw_readl(rng_base);
+
+	return 4;
+}
+
+static struct hwrng ixp4xx_rng_ops = {
+	.name		= "ixp4xx",
+	.data_read	= ixp4xx_rng_data_read,
+};
+
+static int __init ixp4xx_rng_init(void)
+{
+	void __iomem * rng_base;
+	int err;
+
+	rng_base = ioremap(0x70002100, 4);
+	if (!rng_base)
+		return -ENOMEM;
+	ixp4xx_rng_ops.priv = (unsigned long)rng_base;
+	err = hwrng_register(&ixp4xx_rng_ops);
+	if (err)
+		iounmap(rng_base);
+
+	return err;
+}
+
+static void __exit ixp4xx_rng_exit(void)
+{
+	void __iomem * rng_base = (void __iomem *)ixp4xx_rng_ops.priv;
+
+	hwrng_unregister(&ixp4xx_rng_ops);
+	iounmap(rng_base);
+}
+
+subsys_initcall(ixp4xx_rng_init);
+module_exit(ixp4xx_rng_exit);
+
+MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
+MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver for IXP4xx");
+MODULE_LICENSE("GPL");